Effect of Cu and Li addition on the electrical properties of KNN ceramics

In this study, effects of copper oxide addition and lithium modification on the properties of potassium sodium niobate (K
0.5
Na
0.5
)NbO
3
- KNN ceramics were investigated. XRD phase analysis showed that all samples crystallized in pure perovskite phase. CuO addition and Li modification was found to enhance densification of KNN samples. CuO addition was found to lead to higher coupling coefficient (k
p
) and mechanical quality factor (Q
m
), whereas Li modification caused an increase in dielectric constant and piezoelectric charge coefficient (d
33
), and stabilization of the tetragonal phase below room temperature.